Day 4: 11:00 P.M.-12:00 A.M. - S4-E17
Continuity mistake: When Jason and his wife are trying to escape from Marwan, they run through a corridor filled with water puddles. A few seconds later, one of Marwan's men goes through the same corridor to follow them, but none of the puddles had any ripples, which they should have considering the amount of water and time elapsed.
Day 4: 11:00 P.M.-12:00 A.M. - S4-E17
Continuity mistake: When Jack gets out of the helicopter near the reserve power station, he slams the helicopter door, but it immediately bounces back open. In the next shot its closed.
Answer: According to Jack in season 5, Nina was "deep cover" before the pair ever met, so it's safe to assume she was recruited before she joined CTU. As for what her primary mission was, who knows? Perhaps it was to gather sensitive intel and pass it on to her superiors. Given that she worked for an intelligence agency, it's not a stretch. Or perhaps we may find out in season seven.
Cubs Fan ★